Over at ClapClap they've way too much time on their hands. But they spend it wise and have gone absolutely beserk in analyzing the recording history of Leonard Cohen's Hallelujah. It's extensive -- and I mean extensive - complete with graphs and stuff. Definitely fascinating.
Here is a danish version sung by legendary Steffen Brandt and his young apprentice Tina Dickow (Dico). So if you don't know the danish language... enjoy!